Bumper sub and closed fluid circulation assembly

ABSTRACT

A bumper sub and closed fluid circulation assembly wherein the assembly is adapted to be connected in a pipe string having means for closed fluid circulation to provide for limited telescoping movement within the pipe string, and for bumping action as desired.

United States Patent [56] References Cited UNITED STATES PATENTS 12/1953Aruthunoffn........4........ 11/1967 Harrison...

[72] Inventors Damon T.S1ator Houston, Tex.;

yillliiim T; Lee i Harvey, La.; Archie W. 2,664,271 /321 [21] Ap l Nosiids nus ex 3350900 75/321 3,354,950 11 1967 H d 175 321 221 Filed Jan.22, 1970 Y e [45] Patimted 1971 Primary ExaminerJames A. Leppink [73]Assign Bowen Tools Attorney- Pravel, Wilson & Matthews [54] BUMPER SUBAND CLOSED FLUID CIRCULATION ASSEMBLY 10 Claims, 3 Drawing Figs.

l52| U.S. 175/293, ABSTRACT: A bumper sub and closed fluid circulationassemhly wherein the assembly is adapted to be connected in a pipestring having means for closed fluid circulation to provide for limitedtelescoping movement within the pipe string, and for bumping action asdesired.

my FZlbl/IO 50;FieldofSearch............................................ 175/293,321,305,306

PATENTEU AUG! 7 nan SHEET 2 OF 3 llll' lNVIiN'lURS avoided. Suitableapparatus for such closed fluid circulation is disclosed in US. Pat. No.3,208,539.

However, under certain circumstances, such prior apparatus isunsuitable. For example, in offshore drilling, as the ship or floatingdrilling platform goes up and down due to wave action, the length of thedrill string varies so that with such prior apparatus, the weight on thedrill bit fluctuates or the drill bit may even be vertically moved offof the bottom of the hole being drilled. In other instances, in bothoffshore and onshore drilling, it is desirable to provide a bumpingaction to free the pipe string or the bit from a stuck condition in thewell bore, and without pulling the pipe string from the well bore.

SUMMARY OF THE INVENTION This invention relates to a bumper sub andclosed fluid circulation assembly which is adapted to be connected in apipe string having means for closed fluid circulation. With the assemblyof this invention, limited vertical movement within the pipe stringitself may occur without changing the weight on the drill bit.Therefore, drilling operations are substantially unaffected by waveaction offshore within the limits of the vertical movement of theassembly. Also, in coring operations where it is important to maintainsubstantially constant weight on the coring bit, the assembly of thisinvention makes this possible. Bumping can also be accomplished withthis invention without removing the pipe string from the well bore. Inaddition, the assembly may be utilized in any situation wherein it isdesirable or necessary to provide vertical movement or bumping withinthe pipe string itself.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical sectional view,illustrating the apparatus of this invention in a telescoped position;

FIG. 2 is a view similar to FIG. 1, and showing a portion thereof in theextended or bumping position; and

FIGS. 3A, 3B, 3C and 3Dare vertical sectional views of one-half of theapparatus of this invention, with the parts in the telescoped positioncorresponding to FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the letter Adesignates generally the apparatus or assembly of this invention.Briefly, the bumper sub and closed fluid circulation assembly A includesa pair of outer tubular body members and 11 which are disposed inlongitudinally telescoping relationship to each other. Such apparatus Ais adapted to be connected in a pipe string at any suitable point, thelocation of which depends upon the use thereof. For this purpose, theupper end 10a of one of the body members 10 is provided with threads orother means for connecting to the lower end of the pipe string, aportion of which is shown at P in FIG. 1. The lower end of the othertubular body member 11 has threads or other means 11a for connecting tothe upper end of the lower portion of the pipe string P therebelow. Apair of inner pipes 14 and 15 are disposed in longitudinally telescopingrelationship to each other within the outer tubular body members 10 and11, with an annulus 16 formed therebetween for fluid circulation, aswill be more evident hereinafter. The inner pipe 14 is connected to theouter tubular body member 10 by any suitable connection such asconnectors 20, the construction of which will be described hereinafter.The other inner pipe 15 is connected to the outer body member 11 by asimilar connector means 22. The upper end ,of the inner pipe 14 isadapted to be connected with a pipe 60 extending thereabove which formsan extension thereof within the pipe string P, and the lower end of theinner pipe 15 is adapted to be similarly connected to a pipe 61extending therebelow for forming a continuation of such pipe 15downwardly in the portion of the pipe string P below the as sembly A.Various uses of the assembly A are possible, and some of such uses willbe described hereinafter.

Considering the invention more in detail, the outer tubular body memberor mandrel I0 is preferably formed of a pluralivided with a removablemandrel ring 10b having a wearing surface 100 which is contacted by theupper end 11d of the mandrel body 11 when the members 10 and 11 arefully telescoped (FIG. 3A). Splines 10d and 11b (FIG. 3B) interconnectthe members 10 and 11 to prevent relative rotational movementtherebetween while permitting relative longitudinal movementtherebetween.

An annular knocker or hammer l0e is formed on the member or mandrel 10at an intermediate point and it is adapted to be moved longitudinallyinto contact with a hammer or other contact surface 11c which is alsoannular and is a part of the member or mandrel body 11. Such contact isillustrated in FIG. 2 of the drawings. When such contact occurs upon arapid upward movement of the mandrel I0 relative to the mandrel body 11,a bumping action occurs which is transmitted to the entire pipe stringP, and particularly the portion P below. the assembly A.

To facilitate the relative longitudinal movement of the mandrel 10 andthe mandrel body 11, an annular portion is sealed off between themembers 10 and 11 by suitable seals rings 30 at the upper end of themember I1, and lower seal rings 31 at the lower end of the member 11. Alubricant such as oil is disposed between such seals 30 and 31 and isnormally introduced by removing plugs 32 and 33. The lubricant may beintroduced through the opening provided in the member 11 when the plug33 is removed, and with the plug 32 removed. In that way, when thelubricant discharges from the opening provided when the plug 32 isremoved, it is known that the space is substantially filled withlubricant, and the plugs 32 and 33 may be reinserted.

The fixed connection means 20 for connecting the upper I inner pipe ortube 14 to the mandrel 10 includes a ring 35 which is annularly spacedfrom the external surface of the pipe 14 and is connected thereto by aplurality of radial connectors 36. The connection is preferably by welds35a and 36a. The upper section of the mandrel 10 is provided with anannular recess 10f( FIG. 3A) which is of a diameter to receive the ring35 therein. The lower end 40 of the pipe string P is disposed above thering 35 so as to confine the ring 35 within the recess 10f, whereby thering 35 is locked relative to the mandrel 10. Due to the connection ofthe ring 35 to the inner pipe 14 through the radial ribs 36, the pipe 14is fixed with respect to the mandrel 10. Since only three of such ribs36 are required to hold the pipe 14 in the fixed relationship, they donot restrict the flow of fluid in the annulus or annular space I6between the inner pipes 14, I5 and the outer member 10, II.

To assist in holding the inner pipe 14 centrally within the mandrel 10,a plurality of laterally or radially disposed ribs or spacers 50 arepreferably welded or are otherwise secured to the external surface ofthe pipe 14 (FIG. 3A). As shown in FIG. 3A, an additional ring 50a isused to support such ribs 50, and the ring 50a is welded to the pipe 14,with the ribs 50 being welded to the ring 50a. Such spacers or ribs 50may be located at different elevations (FIGS. 3A and 3C) on the pipe 14,depending upon the length of the pipe 14.

The connector 22 (FIGS. 1 and 3D) is preferably the same as theconnector 20, except that it is used for securing the inner pipe 15 tothe mandrel body 11. Thus, the connector 22 has a ring 135, and aplurality of radial ribs or connectors 136 which are welded at 136a and1350. The mandrel body or member 11 has an annular recess lle by meansof an adapter section 1 1 1 having an annular shoulder 1 1 la (FIG. 3D).

A fluid seal is provided between the pipes 14 and 15 by any suitablemeans such as seal rings 55 formed of rubber or other suitable material.Such rings 55 are shown as being on the internal surface of the pipe 15and in sealing engagement with the external surface of the pipe 14. Suchseal is maintained at all times, even when there is relativelongitudinal movement between the pipes 14 and 15.

The upper end of the pipe 14 is connected to a pipe 60 (a portion ofwhich is shown in FIG. 3A) which extends upwardly in the pipe string P,normally to the surface so that the annulus 16 continues all of the wayto the top of the well and is separated from the interior of the pipe 60and the pipes 14 and 15.

Similarly, the lower end of the pipe 15 may be connected to a pipe 61which extends downwardly into the lower portion P of the pipe string,and normally, such lower pipe or pipes 61 will extend downwardly tosubstantially the same point as the lower end of the pipe string P.Usually, the inner pipe 61 and the pipe string portion P terminate withsuitable connectors at a drilling bit or a coring bit. Closed fluidcirculation may thus be maintained throughout the entire pipe string bythe flow of fluid either downwardly or upwardly in the annulus l6 andthen in the opposite direction within the bore of the pipes 61, 15, 14and 60. Thus, the closed fluid circulation may be in either direction sothat circulation of fluid externally of the pipe string is avoided,whereby the danger of losing the fluid in porous formations is avoided.

In the operation or use of the assembly A of this invention, suchassembly A is disposed in a pipe string, usually with drill collars (notshown) above or below the assembly A. In a typical use of the assemblyA, such assembly A is located in a pipe string which is used foroffshore drilling where the drill string moves up and down as thedrilling ship or drilling platform moves up and down due to wave action.With the present invention, as the shipor drilling platform moves up anddown, the outer tubular members 10 and 11 may move up and down relativeto each other within the limits of travel provided by the assembly A,and during such movement, the inner pipes 14 and 15 will likewise moveupwardly and downwardly relative to each other. If the verticalmovements in the pipe string are more than can be realized by a singleassembly A, a plurality of such assemblies A may be incorporated in thesame pipe string so that the drilling bit remains on the bottom andcontinues to drill even though the length of the pipe string is actuallyvarying due to the movements of the ship or drilling platform.

In another example of the use of the apparatus of this invention, thelower end of the pipe string may have a diamond bit or other coring bitthereon which needs a constant weight on the bit to properly perform itscoring operation. Drill collars are then disposed in the pipe stringportion P below the assembly A to place a predetermined load on thecoring bit. The assembly A is in its telescoped position shown in FIG. 1at the start of the drilling so that as drilling proceeds, the drillcollars maintain a constant load on the coring bit while the assembly Ais being extended from its telescoped position of FIG. 1 to the extendedposition of FIG. 2. When the assembly A reaches the position of FIG. 2,the weight on the drill string will immediately increase due to thedrill collars then being supported by the pipe string from the surface,and the operator will then know that he will have to slack off on thepipe string to again telescope or collapse the assembly A to theposition shown in FIG. 1. Thereafter, continued drilling with a constantload from the drill collars may be accomplished.

Should the pipe string P become stuck during drilling operations, theassembly A may be used for imparting a bump by pulling upwardly on thepipe string P to bring the surfaces 10c and 110 together with a bumpingaction.

LII

During all of the various motions and uses of the apparatus A, closedfluid circulation is maintained within the interior of the pipes 14 and15 and the annulus 16. Thus, the assembly A provides a bumper sub withthe means for maintaining the closed fluid circulation in the rest ofthe pipe string.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape, and materials as well as in the details of the illustratedconstruction may be made without departing from the spirit of theinvention.

We claim:

1. A bumper sub and closed fluid circulation assembly adapted to beconnected in a pipe string, comprising:

a pair of outer tubular body members disposed in longitudinallytelescoping relationship to each other;

means for connecting said body members in a pipe string including meanson the upper end of one of said body members for connecting the pipestring and means on the lower end of the other of said body members forconnecting in a pipe string;

a pair of inner pipes disposed in longitudinally telescopingrelationship to each other in said outer tubular body members with anannulus extending longitudinally between said pair of inner pipes andsaid outer tubular body members from the upper end to the lower end ofsaid body members for the flow of fluid therethrough;

a first connector means having longitudinal flow passages therethroughsecuring one of said inner pipes to one of said outer tubular bodymembers and a second connector means having longitudinal flow passagestherethrough securing the other of said inner pipes to the other of saidouter tubular body members for causing said inner pipes to telescope andextend relative to each other as said outer tubular body memberstelescope and extend relative to each other.

2. The structure set forth in claim 1, including:

coacting surfaces on said tubular body members for limiting the extentof telescoping of said members and adapted to be engaged with each otherfor producing a bump in the pipe string.

3. The structure set forth in claim 1, including:

a movable seal means between said inner pipes for preventing fluidleakage therebetween when said pipes are moved longitudinally relativeto each other and when said pipes are stationary relative to each other.

4. The structure set forth in claim 3, including:

coacting surfaces on said tubular body members for limiting the extentof telescoping of said members and adapted to be engaged with each otherfor producing a bump in the pipe string.

5. The structure set forth in claim 1, wherein said means securing eachof said inner pipes to one of said outer tubular body members includes:

a ring spaced radially from the externally surface of each of said innerpipes;

an annular recess in one of said body members for receiving said ring;and

a plurality of radial spacer and connector ribs secured to the internalsurface of said ring and to the external surface of one ofsaid innerpipes.

6. The structure set forth in claim 1, including:

means on said outer tubular body members permitting longitudinalrelative movement therebetween but preventing relative rotationalmovement therebetween.

7. The structure set forth in claim 2, including:

longitudinally spaced seal means between said tubular body members anddisposed above and below said coacting surfaces for providing alubricating chamber therebetween in which lubricant is disposed tofacilitate the telescoping and extension of said body members relativeto each other.

8. The structure set forth in claim 1, including:

LII

string thereabove.

10. The structure set forth in claim 1, including:

means for connecting the upper end of the upper one of said inner pipesto an inner pipe in the portion of the pipe string thereabove; and

means for connecting the lower end of the lower one of said inner pipesto another inner pipe in the portion of the pipe string therebelow.

1. A bumper sub and closed fluid circulation assembly adapted to beconnected in a pipe string, comprising: a pair of outer tubular bodymembers disposed in longitudinally telescoping relationship to eachother; means for connecting said body members in a pipe string includingmeans on the upper end of one of said body members for connecting thepipe string and means on the lower end of the other of said body membersfor connecting in a pipe string; a pair of inner pipes disposed inlongitudinally telescoping relationship to each other in said outertubular body members with an annulus extending longitudinally betweensaid pair of inner pipes and said outer tubular body members from theupper end to the lower end of said body members for the flow of fluidtherethrough; a first connector means having longitudinal flow passagestherethrough securing one of said inner pipes to one of said outertubular body members and a second connector means having longitudinalflow passages therethrough securing the other of said inner pipes to theother of said outer tubular body members for causing said inner pipes totelescope and extend relative to each other as said outer tubular bodymembers telescope and extend relative to each other.
 2. The structureset forth in claim 1, including: coacting surfaces on said tubular bodymembers for limiting the extent of telescoping of said members andadapted to be engaged with each other for producing a bump in the pipestring.
 3. The structure set forth in claim 1, including: a movable sealmeans between said inner pipes for preventing fluid leakage therebetweenwhen said pipes are moved longitudinally relative to each other and whensaid pipes are stationary relative to each other.
 4. The structure setforth in claim 3, including: coacting surfaces on said tubular bodymembers for limiting the extent of telescoping of said members andadapted To be engaged with each other for producing a bump in the pipestring.
 5. The structure set forth in claim 1, wherein said meanssecuring each of said inner pipes to one of said outer tubular bodymembers includes: a ring spaced radially from the externally surface ofeach of said inner pipes; an annular recess in one of said body membersfor receiving said ring; and a plurality of radial spacer and connectorribs secured to the internal surface of said ring and to the externalsurface of one of said inner pipes.
 6. The structure set forth in claim1, including: means on said outer tubular body members permittinglongitudinal relative movement therebetween but preventing relativerotational movement therebetween.
 7. The structure set forth in claim 2,including: longitudinally spaced seal means between said tubular bodymembers and disposed above and below said coacting surfaces forproviding a lubricating chamber therebetween in which lubricant isdisposed to facilitate the telescoping and extension of said bodymembers relative to each other.
 8. The structure set forth in claim 1,including: centralizer ribs secured on the external surface of each ofsaid inner pipes and extending radially into sliding engagement with theinside surface of one of said tubular members to facilitate telescopingand extending of said inner pipes while maintaining said annulus openfor fluid circulation.
 9. The structure set forth in claim 1, including:means for connecting the upper end of the upper one of said inner pipesto an inner pipe in the portion of the pipe string thereabove.
 10. Thestructure set forth in claim 1, including: means for connecting theupper end of the upper one of said inner pipes to an inner pipe in theportion of the pipe string thereabove; and means for connecting thelower end of the lower one of said inner pipes to another inner pipe inthe portion of the pipe string therebelow.